This invention relates to a roll grinding lathe provided with a cambering device.
As is well known in the art, rolls of a rolling mill for manufacturing metal sheets or strips are crowned or cambered for the purpose of producing strips or sheets having a uniform thickness in the transverse direction. For this reason, the roll grinding lathe designed for manufacturing such cambered roll is equipped with a cambering device which controls the position of a grinding wheel so as to finish a roll having a desired cambering profile.
According to a prior art roll grinding lathe of the type referred to above, a cam having a profile corresponding to a desired cambering profile or curve is provided and while a grinding wheel mounted on a grinding wheel head is moved in the longitudinal direction along the barrel surface of a roll to be ground, the cam is rotated in synchronism with the longitudinal movement of the grinding wheel by mechanical means so as to swing the grinding wheel head about a pivot in accordance with the lift of the cam. In other words, the grinding wheel is moved toward and away from the center of the roll to form a desired cambering profile.
One example of the prior art cambering device is shown in FIG. 1. As shown, a horizontal pivot shaft 12 is provided for the lefthand side of a reciprocating carriage 11, and an sub-base 13 is tiltably mounted on pivot 12. One end of a cambering lever 14 is pivotally connected to the upper surface of the reciprocating carriage 11 and a follower roller 15 engaging a cambering cam 16 is mounted on the righthand end of the cambering lever 14.
Although not shown in the drawing, the shaft 17 of cam 16 is connected with a shaft branched from a driving mechanism that moves the reciprocating carriage 11 in the longitudinal direction of pivot shaft 12 so that the shaft 17 is rotated synchronously with the longitudinal movement of the reciprocating carriage by mechanical synchronizing means. The upper surface of lever 14 is urged against a follower roller 18 mounted on the lower end of a bracket 18 secured to the lower surface of the sub-base 13.
A grinding wheel head 19 supporting a grinding wheel 20 and a driving motor thereof, not shown, is slidably mounted on the sub-base 13 so as to be movable in the direction of arrow A, or to be fed toward a roll R to be ground independently of the operation of the cambering cam 16. By adjusting the position of the follower roller 18 with respect to the lever 14, as shown by arrow B, the amount of swinging of the grinding wheel head 19, and hence the angle of rotation of the grinding wheel 20 about pivot shaft 12 which is caused by the rotation of cam 16 can be varied. As shown in FIG. 2, by varying the "lever ratio" as above described various camber profiles l.sub.0, l.sub.1, l.sub.2 and l.sub.3 can be obtained having different amount of cambering. Thus according to the prior art cambering device, the type of the resulting cambering profiles is limited to a group of curves in which the amount of cambering varies at a constant rate as the grinding wheel is moved longitudinally.